CEL: Rear O2, Camshaft, Multiple misfires. Bad idling on startup
08-11-2010, 12:03 PM
#1
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Join Date: Jan 2009
Posts: 22
CEL: Rear O2, Camshaft, Multiple misfires. Bad idling on startup
Alright, I've had problems with my idle speed for a while when the engine is cold. 245k on the car. When I first start up, my car will sputter and stall several times before I'm able to get off. Once I accelerate though, this problem goes away.
I've been having trouble passing emissions. I had codes for both of the front O2 sensors. I cleaned them, reset, drove, and had it tested. The light came back on as she was testing it -.-, failed for all 3 O2 sensors. I changed both of the front O2 sensors, reset, and the light comes back on the 2nd start, gives code for the rear O2 sensor. I take the car to the shop the other day, they read the codes, reset, and tell me that my ECU is probably bad, because they got more codes than just O2 sensors now. I come home, do a reset myself last night. I start up this morning, CE lights off, everything's fine. I get about 6 starts, still having the startup idle/stalling problems, and the 7th when I put the car in reverse the CEL comes back on. I drive home, read the codes and I have 0101- Camshaft position sensor, 0701 - multiple cylinder misfire (i'm guessing from the stalling), and 0707 for the rear sensor. I personally think my ECU is fine. I've cleaned my TB, EGR tubes, IACV, and MAF recently, and changed my fuel filter to fix a stalling problem I was having.
Do you think my ECU is actually bad, or do you think replacing the rear O2 sensor and Cam position sensor will fix the codes and allow me to pass emissions?
Also, could this possibly fix the problems I'm having with stalling on startup?
P.S. Any advice on the prodecures to change the Camshaft Position Sensor and Rear O2 Sensor would be great too. Could anyone tell me where to find each, how difficult they are to change, ect?
I've been having trouble passing emissions. I had codes for both of the front O2 sensors. I cleaned them, reset, drove, and had it tested. The light came back on as she was testing it -.-, failed for all 3 O2 sensors. I changed both of the front O2 sensors, reset, and the light comes back on the 2nd start, gives code for the rear O2 sensor. I take the car to the shop the other day, they read the codes, reset, and tell me that my ECU is probably bad, because they got more codes than just O2 sensors now. I come home, do a reset myself last night. I start up this morning, CE lights off, everything's fine. I get about 6 starts, still having the startup idle/stalling problems, and the 7th when I put the car in reverse the CEL comes back on. I drive home, read the codes and I have 0101- Camshaft position sensor, 0701 - multiple cylinder misfire (i'm guessing from the stalling), and 0707 for the rear sensor. I personally think my ECU is fine. I've cleaned my TB, EGR tubes, IACV, and MAF recently, and changed my fuel filter to fix a stalling problem I was having.
Do you think my ECU is actually bad, or do you think replacing the rear O2 sensor and Cam position sensor will fix the codes and allow me to pass emissions?
Also, could this possibly fix the problems I'm having with stalling on startup?
P.S. Any advice on the prodecures to change the Camshaft Position Sensor and Rear O2 Sensor would be great too. Could anyone tell me where to find each, how difficult they are to change, ect?
Last edited by Pint07; 08-11-2010 at 12:12 PM.
08-11-2010, 12:14 PM
#2
test the sensor first to see if it's getting correct voltage. you can search for a manual on here.
as for the rear o2: use wd-40 or pb blaster on it before you try to take it out. just changed one on our car about two weeks ago. don't be freaked out by the wiring harness going into the car's body
just take that rubber thing off and gently pull on the harness until you see the connector come out.
however, you've said that the ecu threw the code for the front sensors. have you replaced those at all? be prepared for a possibility of them coming back after you change the rear one.
as for the rear o2: use wd-40 or pb blaster on it before you try to take it out. just changed one on our car about two weeks ago. don't be freaked out by the wiring harness going into the car's body
just take that rubber thing off and gently pull on the harness until you see the connector come out. however, you've said that the ecu threw the code for the front sensors. have you replaced those at all? be prepared for a possibility of them coming back after you change the rear one.
08-11-2010, 12:16 PM
#3
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Thread Starter
Join Date: Jan 2009
Posts: 22
test the sensor first to see if it's getting correct voltage. you can search for a manual on here.
as for the rear o2: use wd-40 or pb blaster on it before you try to take it out. just changed one on our car about two weeks ago. don't be freaked out by the wiring harness going into the car's body just take that rubber thing off and gently pull on the harness until you see the connector come out.
however, you've said that the ecu threw the code for the front sensors. have you replaced those at all? be prepared for a possibility of them coming back after you change the rear one.
as for the rear o2: use wd-40 or pb blaster on it before you try to take it out. just changed one on our car about two weeks ago. don't be freaked out by the wiring harness going into the car's body
just take that rubber thing off and gently pull on the harness until you see the connector come out. however, you've said that the ecu threw the code for the front sensors. have you replaced those at all? be prepared for a possibility of them coming back after you change the rear one.
I don't have any way of testing the voltage :\
08-11-2010, 12:17 PM
#4
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Join Date: Sep 2009
Location: Worcester, MA
Posts: 4,011
ECU dont sound bad to me man. Sounds like u have a bad rear o2 sensor and need to test Camshaft position sensor (CPS) per FSM. A bad CPS will def cause misfires and all type of issues.
rear o2 sensor u gonna hafta lift the car. Its downstream of the cat.
THe CPS is a sensor on the engine across from the PS reservoir. Its the only sensor there inserted into the engine. Check sensor for fouling and check harness for damage.
rear o2 sensor u gonna hafta lift the car. Its downstream of the cat.
THe CPS is a sensor on the engine across from the PS reservoir. Its the only sensor there inserted into the engine. Check sensor for fouling and check harness for damage.
08-11-2010, 12:28 PM
#5
i didn't lift the car when i did ours lol
it's on the driver's side right after the cat (think driver's door area).
p.s. this guy is selling a cps for $15 shipped. http://forums.maxima.org/4th-generat...-trim-etc.html
it's on the driver's side right after the cat (think driver's door area).
p.s. this guy is selling a cps for $15 shipped. http://forums.maxima.org/4th-generat...-trim-etc.html
Last edited by 99zx2; 08-11-2010 at 12:30 PM.
08-11-2010, 12:47 PM
#7
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Join Date: Jan 2010
Location: albany ny
Posts: 84
your mileage is a testiment to how well these cars are built as for your problems ive had them all and more and in ny we have high emission standards you should just replace your 02 sensors and your cam position sensor with sensors you are 100 percent sure are good but you should clean the idle air contol or for those of us who have a thesaurus iacv its the part by the throttle body that allows a predispositioned amount of air from one side of the throttle body to the other to keep the car running when cold or you come to a stop
08-11-2010, 12:49 PM
#8
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Join Date: Sep 2009
Location: Worcester, MA
Posts: 4,011
i didn't lift the car when i did ours lol
it's on the driver's side right after the cat (think driver's door area).
p.s. this guy is selling a cps for $15 shipped. http://forums.maxima.org/4th-generat...-trim-etc.html
it's on the driver's side right after the cat (think driver's door area).
p.s. this guy is selling a cps for $15 shipped. http://forums.maxima.org/4th-generat...-trim-etc.html
U might need a screwdriver or a wrench, thats about it. Its literally one bolt on the front of the engine near the front valve cover .
08-11-2010, 01:03 PM
#9
Member who somehow became The President of The SE-L Club
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Posts: 16,033
Your ECU is fine.
Never go back to the shop that told you the ECU might be bad just because there was more then just your o2 code.
The CPS (cam position) is what times fuel delivery. Fix that first, clear the error codes and see what comes back. That in itself, may solve some of your issues.
Never go back to the shop that told you the ECU might be bad just because there was more then just your o2 code.
The CPS (cam position) is what times fuel delivery. Fix that first, clear the error codes and see what comes back. That in itself, may solve some of your issues.
08-11-2010, 01:37 PM
#10
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Join Date: Jan 2010
Location: albany ny
Posts: 84
in total agreeance any shop that says your ecu is bad is just hunting for money ive seen shops say anything to get money one guy tried to tell a girl i know she needed a timing belt on her 4th gen and i said to the guy that might be kind of hard he said he does lots of them and i said hard because there isnt one and he got real nervous
08-11-2010, 02:16 PM
#11
Alright, I've had problems with my idle speed for a while when the engine is cold. 245k on the car. When I first start up, my car will sputter and stall several times before I'm able to get off. Once I accelerate though, this problem goes away.
I've been having trouble passing emissions. I had codes for both of the front O2 sensors. I cleaned them, reset, drove, and had it tested. The light came back on as she was testing it -.-, failed for all 3 O2 sensors. I changed both of the front O2 sensors, reset, and the light comes back on the 2nd start, gives code for the rear O2 sensor. I take the car to the shop the other day, they read the codes, reset, and tell me that my ECU is probably bad, because they got more codes than just O2 sensors now. I come home, do a reset myself last night. I start up this morning, CE lights off, everything's fine. I get about 6 starts, still having the startup idle/stalling problems, and the 7th when I put the car in reverse the CEL comes back on. I drive home, read the codes and I have 0101- Camshaft position sensor, 0701 - multiple cylinder misfire (i'm guessing from the stalling), and 0707 for the rear sensor. I personally think my ECU is fine. I've cleaned my TB, EGR tubes, IACV, and MAF recently, and changed my fuel filter to fix a stalling problem I was having.
Do you think my ECU is actually bad, or do you think replacing the rear O2 sensor and Cam position sensor will fix the codes and allow me to pass emissions?
Also, could this possibly fix the problems I'm having with stalling on startup?
P.S. Any advice on the prodecures to change the Camshaft Position Sensor and Rear O2 Sensor would be great too. Could anyone tell me where to find each, how difficult they are to change, ect?
I've been having trouble passing emissions. I had codes for both of the front O2 sensors. I cleaned them, reset, drove, and had it tested. The light came back on as she was testing it -.-, failed for all 3 O2 sensors. I changed both of the front O2 sensors, reset, and the light comes back on the 2nd start, gives code for the rear O2 sensor. I take the car to the shop the other day, they read the codes, reset, and tell me that my ECU is probably bad, because they got more codes than just O2 sensors now. I come home, do a reset myself last night. I start up this morning, CE lights off, everything's fine. I get about 6 starts, still having the startup idle/stalling problems, and the 7th when I put the car in reverse the CEL comes back on. I drive home, read the codes and I have 0101- Camshaft position sensor, 0701 - multiple cylinder misfire (i'm guessing from the stalling), and 0707 for the rear sensor. I personally think my ECU is fine. I've cleaned my TB, EGR tubes, IACV, and MAF recently, and changed my fuel filter to fix a stalling problem I was having.
Do you think my ECU is actually bad, or do you think replacing the rear O2 sensor and Cam position sensor will fix the codes and allow me to pass emissions?
Also, could this possibly fix the problems I'm having with stalling on startup?
P.S. Any advice on the prodecures to change the Camshaft Position Sensor and Rear O2 Sensor would be great too. Could anyone tell me where to find each, how difficult they are to change, ect?
08-11-2010, 06:44 PM
#12
Go to the dealership if CPS is defective and get a 10mm wrench and ew and change it yourself. This does not need a write up as it is self explanatory. Some may say don't go to the dealership for the sensor but imporrtant ones like these, I rather spend the money and be satisfied I got something of high quality.
Last edited by Trini Boom; 08-18-2010 at 06:20 AM.
08-17-2010, 09:55 PM
#13
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Join Date: Jan 2009
Posts: 22
Update: Okay, today I changed the CPS. Cleared codes, drove it a bit. Then I start my car back up later and the CEL comes back on. The rear O2 sensor code is gone, and I'm getting codes for the front 2, that I just changed. This is pissing me off. I'm so confused right now.
08-17-2010, 10:50 PM
#14
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Join Date: Jun 2009
Location: Baltimore, MD
Posts: 242
Update: Okay, today I changed the CPS. Cleared codes, drove it a bit. Then I start my car back up later and the CEL comes back on. The rear O2 sensor code is gone, and I'm getting codes for the front 2, that I just changed. This is pissing me off. I'm so confused right now.
08-18-2010, 11:31 AM
#15
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Thank you. So much.
08-18-2010, 12:20 PM
#16
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Location: Baltimore, MD
Posts: 242
Glad to have help... and you're not dumb at all, the mechanic is the one dumb. The org rocks
Last edited by najee1062; 08-18-2010 at 12:24 PM.
08-21-2010, 05:50 PM
#19
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Thread Starter
Join Date: Jan 2009
Posts: 22
The light is still off. I'm still having the stalling problems on start up, but I can deal with that. I'm guessing that's a fuel pressure regulator problem or something like that.
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